Polyembryony, Biology

Assignment Help:

Polyembryony

Presence of more than one embryo in a seed is termed polyembryony. The phenomenon, first discovered in orange seeds by Leeuwenhoek (1719), attracted considerable attention because of its potential for application in and horticulture. Polyembryony is broadly classified into simple and multiple, depending on whether the supernumerary arises in one or more embryo sacs in the ovule. Simple polyembryony may be sexual or asexual. In sexual polyembryony embryos may originate from the fertilized egg and synergids, or by budding or cleavage of the polyembryony cells or suspensor of the zygotic embryo.

Asexual embryos are produced within the embryo sac without fertilization. Embryos may also originate from diploid nucellar or integumentary cells of the ode and grow into the embryo sac. These embryos are termed adventive or sporophytic. Multiple polyembryonies involve production of accessory embryos from two or more embryo sacs in the same ovule. For example, in the sea Island cotton, Gossypium barbadense, fertilization of egg in one embryo sac stimulates the induction of embryo from an unfertilized egg in the adjacent embryo sac within the same ovule. Thus, diploid-haploid twin embryos are produced in the seed.


Related Discussions:- Polyembryony

Temperature-environmental components, TEMPERATURE Temperature is a majo...

TEMPERATURE Temperature is a major physical environmental factor which profoundly influences the vital activities of living organisms like, metabolism, growth and reproduction.

Advantages and disadvantages of measurement of cell mass, Define Advantages...

Define Advantages and Disadvantages of Measurement of Cell Mass? Advantage 1. It is a useful technique for estimating fungal and actinomycetes growth. Disadvantages 1.

Cannulation-procedures of oxygenators, Cannulation :  Typically blood is d...

Cannulation :  Typically blood is drained by gravity through two cannulae inserted into the superior and inferior vena cavae. During bypass, if the SVC and IVC are snared, the ent

What is gene therapy, What is Gene therapy Gene therapy targets non ger...

What is Gene therapy Gene therapy targets non germ line cells, ie somatic cells, so will not directly affect gene pool. The frequency of the allele for the genetic disease w

What is a recessive gene, What is a recessive gene? With the birth of a...

What is a recessive gene? With the birth of a child, it gets its genes from both parents. Some genes 'override' other genes. Using hair color as instance: If single parent i

Illustrating how neuropsychologists evaluate young children, Illustrating h...

Illustrating how neuropsychologists evaluate young preschool children, older children, youngster adults, and elderly adults. The brain is an evolving organ and functions very

Phylum placozoa, Phylum Placozoa The phylum Placozoa contains a single...

Phylum Placozoa The phylum Placozoa contains a single species of a minute marine animal Trichoplax adharens composed of a dorsal and ventral epithelial layer enclosing loose m

Explain the life cycle of the gymnosperms, Q. What is the life cycle of the...

Q. What is the life cycle of the gymnosperms? As all plants they present a diplobiontic life cycle that is alternation of generations with haploid and diploid stages and the la

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd